On most vessels, the emergency generator/switchboard room is located as high above the waterline as practicable and the room enclosure, doors, and ventilators are rendered weathertight. This location serves to protect against the ingress of sea water in heavy weather conditions. However, at boat deck level, the emergency generator room deckhead on the MORUY was extensively corroded. This allowed rainwater and sea spray to leak into the compartment below where it flowed along a series of electrical cables leading to the emergency switchboard. Because the cable glands entering the switchboard were not weathertight, the water penetrated the switchboard and caused electrical grounds and short circuiting, which affected one hydraulic steering pump unit, alarm/indicator lights, and the rudder angle indicator. Had the deckhead been permanently repaired and properly hose-tested during the previous month when its deteriorated condition first became known in dry dock, such water damage to the emergency switchboard would not have occurred during the voyage within Canadian waters. It is standard practice for a vessel such as the MORUY to have both pump units in operation when manoeuvring in confined waters. However, it is not known whether both steering pumps or just one had been operating prior to the accident and it is not known with certainty why, just prior to the grounding, the vessel failed to respond to the helm when the navigating crew switched the steering control from one control system to the other. If only one pump unit was in service at the time of the electrical failure, it could have contributed to a momentary loss of steering capability during the emergency switch-over process. On the MORUY, one steering control system received electrical power from the main switchboard, and the other from the emergency switchboard. When the emergency switchboard was disabled by water entry, control power was still available from the main switchboard. However, the rudder angle indicator and steering station alarms and warning lights ceased to function, when the 24-volt control power from the emergency switchboard was disrupted. Consequently, the bridge crew were unable to ascertain the operational status of the steering gear. However, an inspection of the system revealed that the steering gear control system powered via the main switchboard was still operational. Had an alternative power circuit and source been available to the bridge control panel alarms and indicator lights, the helmsman and OOW would have been aware of the true operational status of the steering system and they could have continued to navigate the vessel within the channel and avoided grounding.Analysis On most vessels, the emergency generator/switchboard room is located as high above the waterline as practicable and the room enclosure, doors, and ventilators are rendered weathertight. This location serves to protect against the ingress of sea water in heavy weather conditions. However, at boat deck level, the emergency generator room deckhead on the MORUY was extensively corroded. This allowed rainwater and sea spray to leak into the compartment below where it flowed along a series of electrical cables leading to the emergency switchboard. Because the cable glands entering the switchboard were not weathertight, the water penetrated the switchboard and caused electrical grounds and short circuiting, which affected one hydraulic steering pump unit, alarm/indicator lights, and the rudder angle indicator. Had the deckhead been permanently repaired and properly hose-tested during the previous month when its deteriorated condition first became known in dry dock, such water damage to the emergency switchboard would not have occurred during the voyage within Canadian waters. It is standard practice for a vessel such as the MORUY to have both pump units in operation when manoeuvring in confined waters. However, it is not known whether both steering pumps or just one had been operating prior to the accident and it is not known with certainty why, just prior to the grounding, the vessel failed to respond to the helm when the navigating crew switched the steering control from one control system to the other. If only one pump unit was in service at the time of the electrical failure, it could have contributed to a momentary loss of steering capability during the emergency switch-over process. On the MORUY, one steering control system received electrical power from the main switchboard, and the other from the emergency switchboard. When the emergency switchboard was disabled by water entry, control power was still available from the main switchboard. However, the rudder angle indicator and steering station alarms and warning lights ceased to function, when the 24-volt control power from the emergency switchboard was disrupted. Consequently, the bridge crew were unable to ascertain the operational status of the steering gear. However, an inspection of the system revealed that the steering gear control system powered via the main switchboard was still operational. Had an alternative power circuit and source been available to the bridge control panel alarms and indicator lights, the helmsman and OOW would have been aware of the true operational status of the steering system and they could have continued to navigate the vessel within the channel and avoided grounding. Two days prior to the grounding, water entered the emergency switchboard, causing loss of power to navigation instruments and steering equipment. The emergency generator room deckhead was temporarily repaired but not tested weathertight before the vessel proceeded up the St. Lawrence River. When the vessel neared Champlain, the effect of water and dirt in the emergency switchboard caused a partial electrical failure for a second time in Canadian waters. The vessel suffered a temporary loss of power to the steering equipment, and permanent loss of power to the rudder angle indicator and steering gear indicator lights. After the power failure, one steering pump was operational and one means of steering control was still available at the helm position on the bridge. The navigating personnel could not determine that the steering gear was still operational. The MORUY grounded, causing damage to the forepeak tank. The extensively corroded condition of the emergency generator room deckhead was known to the crew prior to the vessel entering Canadian waters. International regulations do not require redundant electrical circuits for rudder angle indicators or alarm /indicator lights. The design of the steering control system and instrumentation met all applicable international regulations.Findings Two days prior to the grounding, water entered the emergency switchboard, causing loss of power to navigation instruments and steering equipment. The emergency generator room deckhead was temporarily repaired but not tested weathertight before the vessel proceeded up the St. Lawrence River. When the vessel neared Champlain, the effect of water and dirt in the emergency switchboard caused a partial electrical failure for a second time in Canadian waters. The vessel suffered a temporary loss of power to the steering equipment, and permanent loss of power to the rudder angle indicator and steering gear indicator lights. After the power failure, one steering pump was operational and one means of steering control was still available at the helm position on the bridge. The navigating personnel could not determine that the steering gear was still operational. The MORUY grounded, causing damage to the forepeak tank. The extensively corroded condition of the emergency generator room deckhead was known to the crew prior to the vessel entering Canadian waters. International regulations do not require redundant electrical circuits for rudder angle indicators or alarm /indicator lights. The design of the steering control system and instrumentation met all applicable international regulations. The vessel grounded after water leaked through a corroded deckhead and into the emergency switchboard housing, causing short-circuiting and loss of electrical power to the steering control systems. Contributing to the occurrence was the lack of maintenance on the deck over the emergency generator room, the dirty condition of the switchboard, and the lack of an alternate power system to the rudder angle indicator and steering gear alarms/indicator lights on the bridge.Causes and Contributing Factors The vessel grounded after water leaked through a corroded deckhead and into the emergency switchboard housing, causing short-circuiting and loss of electrical power to the steering control systems. Contributing to the occurrence was the lack of maintenance on the deck over the emergency generator room, the dirty condition of the switchboard, and the lack of an alternate power system to the rudder angle indicator and steering gear alarms/indicator lights on the bridge. As a result of this, and several other occurrences, TCMS - Quebec City has completed a study on steering gear failures. Consequently, TCMS will introduce a proposal to amend TP 127 Ship Electrical Standards to provide a redundancy in the steering gear remote control system, alarm and indication system, and the electrical supply to the rudder angle indicator. They will be introduced to the Design and Engineering Working Group at the Canadian Marine Advisory Council early in 2000.Safety Action Taken As a result of this, and several other occurrences, TCMS - Quebec City has completed a study on steering gear failures. Consequently, TCMS will introduce a proposal to amend TP 127 Ship Electrical Standards to provide a redundancy in the steering gear remote control system, alarm and indication system, and the electrical supply to the rudder angle indicator. They will be introduced to the Design and Engineering Working Group at the Canadian Marine Advisory Council early in 2000.